Sign up to receive free email alerts when patent applications with chosen keywords are publishedSIGN UP

Abstract:

A device for inducing weight loss in a patient includes a tubular
prosthesis self-expandable from a collapsed position in which the
prosthesis has a first diameter to an expanded position in which the
prosthesis has a second, larger, diameter. In a method for inducing
weight loss, the prosthesis is placed in the collapsed position and
inserted into a stomach of a patient. The prosthesis is allowed to
self-expand from the collapsed position to the expanded position and into
contact with the walls of the stomach, where it induces feelings of
satiety and/or inhibits modulation of satiety-controlling factors such as
Ghrelin.

Claims:

1. A method for treating obesity in a patient, comprising providing an
intestinal sleeve device comprising (i) an elongate polymeric sleeve at
least 20 cm in length and extending between proximal and distal open
ends, to act as an absorption barrier within the duodenum, (ii) disposed
within the sleeve, a self-expanding structure adapted, in its expanded
form, and with the device positioned entirely within the small intestine
of the subject, to press against the sides of walls of the intestine to
anchor the sleeve within the duodenum, and (iii) surface features adapted
to hold the sleeve in place within the duodenum when the device is
positioned entirely within the small intestine of the patient and the
self-expanding structure is expanded to press the sleeve against the
walls of the intestine, passing the entire intestinal sleeve device in a
distal direction through the patient's esophagus and into the small
intestine of the patient; and expanding the self-expanding structure in
the device, thereby anchoring the sleeve device within the duodenum of
the intestine, such that food from the stomach flows through the
intestinal sleeve device within the duodenum, thereby limiting absorption
of food through the walls of the duodenum.

2. The method of claim 1, wherein the sleeve device is anchored within
the duodenum with its proximal end adjacent, and at least one centimeter
downstream of, the ampulla of vader.

3. The method of claim 1, wherein said surface features are scales or
barbs.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a continuation of U.S. patent
application Ser. No. 13/247,377, filed Sep. 28, 2011, now, which is a
continuation of U.S. patent application Ser. No. 12/538,741, filed Aug.
10, 2009, now, which is a continuation of U.S. patent application Ser.
No. 10/457,144, filed Jun. 9, 2003, now abandoned, which is a divisional
of U.S. patent application Ser. No. 09/940,110, filed Aug. 27, 2001, now
U.S. Pat. No. 6,675,809.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of devices and
methods for achieving weight loss in humans, and, specifically to the use
of devices implantable within the human stomach for controlling feelings
of hunger.

BACKGROUND OF THE INVENTION

[0003] Various medical approaches are used for controlling obesity. These
approaches include diet, medication, and surgical procedures. One of the
more successful surgical procedures is the vertical banded gastroplexy or
the proximal gastric pouch with a Roux-en-Y anastomosis. However, known
complications are present with each of these procedures and more
successful options are desired.

[0004] Other alternatives include implantation of gastric balloons that
prevent overeating by occupying volume within the stomach. Unfortunately,
gastric balloons can migrate down the GI tract, causing obstruction and
thus necessitating removal.

[0005] It is therefore desirable to provide a successful and
minimally-invasive alternative to existing approaches for controlling
obesity.

SUMMARY OF THE INVENTION

[0006] A satiation device utilizing principles of the present invention
includes a tube having a collapsed position proportioned to permit
introduction of the tube into a portion of the stomach. Once positioned
within the body, the tube self-expands into contact with the interior of
the stomach. During use, food ingested into the stomach passes through
the tube. In an alternate embodiment, the tube may be formed of a
material that prevents food within the tube from contacting the
surrounding walls of the stomach. In one embodiment, the tube may be
positionable within the antrum of the stomach. In other alternative
embodiments, the device may include a fundal basket which mayor may not
be attached to a proximal end of an antral tube, and/or a bowel tube
which mayor may not be attached to a distal end of an antral tube.

[0007] In other alternative embodiments, a small pouch is attached to a
cage structure such as a fundal basket and positioned at the proximal end
of the stomach. In other alternative embodiments, this pouch may he
provided without a cage structure and is independently secured against
the proximal stomach wall by endoscopy guided sutures or other means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a schematic illustration of a human stomach and a portion
of the small intestine.

[0009] FIG. 2 is a plan view of a satiation device utilizing principles of
the present invention.

[0010] FIG. 3 is a plan view of a satiation device similar to that of FIG.
2, but including a drug delivery reservoir.

[0011]FIG. 4A is a schematic illustration of a stomach, pylorus, and
bowel, showing introduction of the device of FIG. 2 or 3 into the antrum.

[0012]FIG. 4B is a schematic illustration similar to FIG. 4A, showing the
device in position.

[0013]FIG. 4c is a schematic illustration similar to FIG. 4B, showing
withdrawal of the device into a sheath for subsequent removal from the
body.

[0014] FIG. 5 is a schematic illustration similar to the illustration of
FIG. 4B, showing the position of an alternative device having an antral
tube and a bowel tube.

[0015] FIG. 6 is a schematic illustration similar to the illustration of
FIG. 4B, showing the position of an alternative device having an antral
tube that does not cross the pyloric sphincter.

[0016] FIG. 7 is a plan view of an antral tube similar to the antral tube
of FIG. 6, with retaining structures formed into the external surface.

[0017] FIG. 8 is a plan view of an antral tube similar to the antral tube
of FIG. 6, with retaining structures formed at the proximal and distal
ends.

[0018] FIGS. 9A and 9B are plan views of antral tubes similar to the
antral tube of FIG. 6, with variations of retaining ridges formed on
their external surfaces.

[0035] An anatomical view of a human stomach S and associated features is
shown in FIG. 1. Stomach S includes a fundus F at its proximal end and an
antrum A at its distal end. Antrum A feeds into the pylorus P which
attaches to the duodenum D, the proximal region of the small intestine.
Within the pylorus P is a sphincter that prevents backflow of food from
the duodenum D into the stomach. The middle region of the
small-intestine, positioned distally of the duodenum D, is the jejunum J.

[0036] Various embodiments of satiation devices are described herein. Many
of these devices include an antral tube positionable within the antrum A,
and may optionally include a fundal tube connected to the proximal end of
the antral tube for placement in the fundus F, and/or a bowel tube
connected to the distal end of the antral tube for placement in the
duodenum D.

[0037] The device may be modular in that the various components may be
provided separate from one another. In such a modular system, the
separate implanted components may be attached to one another within the
body during implantation, or certain ones of them may remain unattached
to one another even after implantation. Alternatively, the physician may
assemble the components to one another just prior to implantation.
Modular components are desirable in that they permit the physician to
select sizes for each component that are appropriate for the patient. As
another alternative, the device may be a unitary device in the sense that
the components (e.g. the antral tube, bowel tube and/or fundal basket)
are not separately provided but instead form a single-unit implant.

[0038] FIG. 2 shows a first embodiment of a satiation device 100 utilizing
principles of the present invention. Satiation device 100 includes an
elongate tubular body 10 having a proximal section 12 and a distal
section 14. Proximal section 12 includes a reduced diameter neck 16.
Distal section 14 preferably has an hourglass profile including a pair of
broadened sections 18 and a waisted section 20 between the broadened.
sections.

[0039] Tubular body 10 is proportioned to be at least partially positioned
within the antrum of the stomach such that food moving into the antrum
passes through the hollow interior of the tubular body. The tubular body
10 (which will also be referred to as the antral tube) may be made of
shape memory materials such as nitinol or other shape memory alloys, or
shape memory polymers, and is preferably made of a soft mesh or other
framework formed of nitinol or stainless steel wires in combination with
a polymeric barrier that prevents ingested food passing through the
antral tube 10 from contacting the walls of the antrum. Thus, the
polymeric barrier may be a skin formed on the exterior or interior of the
mesh, or the mesh may be encapsulated in polymeric material or the
polymer may be disposed in the interstices of the mesh. By preventing
food from contacting the antrum walls as it passes from mid-stomach to
the pylorus, the device prevents modulation of Ghrelin or other satiety
controlling factors.

[0040] As shown in FIG. 3, the device 100 may optionally include one or
more pharmaceutical delivery reservoirs 22, which are filled with
substances known to inhibit release of Ghrelin or other hormones
associated with feelings of satiety. Such substances may be chemical or
pharmaceutical substances, therapeutic molecules or cells, or genetic
material. Each such reservoir 22 may comprise a fluid pocket formed
between a first layer of fluid impermeable polymeric material and a
second layer of semi-permeable membrane that allows the substances to
pass from the reservoirs into the surrounding tissue. Alternatively, the
polymeric material used to form the tube may be impregnated with
substances useful for maintaining low Ghrelin levels.

[0041] The reservoir or material containing the inhibitive substances may
be in a portion of the device that lies within the antrum and/or in a
portion that lies within the duodenum, particularly the segment of the
duodenum that is proximal of the ampulla of vader, as it is believed that
receptors for such substances are present in these areas.

[0042] During implantation, the antral tube 10 is passed into the patient
blindly, under radiologic guidance, or under endoscopic guidance. Prior
to implantation. the antral tube 10 is preferably packaged in a tubular
sheath 26 (see FIG. 4A) by compressing the antral tube 10 about its
longitudinal axis and inserting it into tubular sheath 26.

[0043] The sheath 26, with the antral tube 10 packaged inside, is passed
into the stomach via the patient's mouth and positioned within the antrum
as shown in FIG. 4A. The antral tube 10 is then pushed out the distal end
of the sheath 26 using a pushing device 28 inserted into the proximal end
of the sheath. The mesh forming the antral tube is preferably constructed
so as to be self-expanding, such that the tube 10 springs radially open
into an expanded condition upon its ejection from the sheath 26. When in
its expanded condition, the antral tube exerts pressure against the
interior surfaces against which it is in contact, so as to create the
feeling of satiety and to inhibit Ghrelin release. The radial pressure of
the device against the walls also secures the device against the walls of
the antrum and prevents it from moving through the pylorus, even in the
presence of peristalsis. In an alternative embodiment, the antral section
is covered, such as by a polymeric material, shielding the stomach
contents from the antrum. This may suppress chemical mediators of the
sensation of hunger, such as Ghrelin production.

[0044] The hour-glass shape of the distal portion 14 is configured such
that when the device is implanted, the waist section 20 becomes seated at
the pyloric sphincter as shown in FIG. 4B. This helps to prevent
migration of the device within the stomach, yet because of the
self-expanding nature will avoid obstruction of the pylorus. It may be
additionally desirable to provide the antral tube to include a valve (not
shown) within the waist section 20, so as to prevent reflux of bile from
the duodenum into the antrum.

[0045] Referring to FIG. 4c, removal of the device is carried out by
inserting sheath 26 into the stomach, and by extending a grasping
instrument such as snare 30 through the sheath. Snare 30 is closed around
the neck 16 of the tube 10 and withdrawn, causing the tube 10 to collapse
and be drawn into the sheath 26. Once the tube 10 is stored within the
sheath, the sheath is withdrawn from the patient.

[0046] It will be appreciated that various other mechanisms may be used to
facilitate collapse of the tube for removal. For example, FIGS. 16A and
16B show end views of the proximal portion of an alternative antral tube
11 which is provided to include one or more radially extending tabs 13.
Tabs 13 are preferably rounded and smooth to minimize interference with
flow through the tube 11. When the satiation device is to be removed,
tabs 13 are drawn inwardly using endoscopic instruments, causing the tube
to collapse inwardly.

[0047] Referring to FIG. 5, an alternate embodiment of satiation device
110 includes an antral tube 10a similar to that of the previous
embodiments, but additionally includes a small diameter bowel tube 32 at
its distal end. The bowel tube 32 is preferably formed of a combination
of mesh and polymer as described in connection with antral tube 10 of
FIG. 2. It simulates a Roux en Y, or gastric bypass, procedure by keeping
food away from the proximal portion of the small bowel (i.e. away from
the duodenum or the jejunum and duodenum, the portions of the small
intestine at which most carbohydrates and proteins are absorbed by the
body). This in turn prevents absorption of food by the proximal portion
of the small bowel, and thus reduces the total amount of food absorbed by
the body.

[0048] The bowel tube 32 is smaller in diameter than the antral tube 10a,
and is of a diameter that will allow it to press gently against the walls
of the small bowel. It must also be sufficiently flexible to pass
posteriorly and distally into the second portion of the duodenum without
damaging the mucosa. This may be facilitated by the use of a guidewire
that is first introduced with an endoscope.

[0049] The bowel tube 32 may be a soft wire mesh (formed, for example, of
shape memory alloys, nitinol. stainless steel alloys, stainless steel or
polymers including shape memory polymers) covered with a polymer to
prevent food and digestive juices from contacting the mucosa of the
duodenum. Tube 32 may be provided to have a valve 34 at its distal end,
which functions to prevent reflux of intestinal contents. The bowel tube
includes an opening 33 to ensure that the ampulla of vader is not
obstructed.

[0050] Delivery of the device 110 into, and its removal from the stomach
may be performed under radiological or endoscopic guidance as described
with respect to the prior embodiments. A conventional guide wire may also
be used to facilitate positioning of the bowel tube 32. If a guide wire
is used, it is first placed into the duodenum using endoscopy or
radiology to guide the wire placement. The bowel tube 32 and antral tube
10a are then placed over the wire and guided over the wire into the
duodenum or jejunum to the desired location. Next, the guide wire is
removed. The small bowel tube position is maintained by bearing against
the proximal end of the antral tube using a pushing instrument (such as
the pusher 28 shown in FIG. 4A), while the covering sheath is withdrawn.
As they are released from the sheath, the small bowel tube and the antral
tube deploy and expand into contact with the antrum walls.

[0051] In a modular version of the device 110, the antral tube 10a and
bowel tube 32 may be provided separately. Components of a modular system
may be attached to one another pre-operatively or after each component
has been positioned within the body.

[0052] An alternative form of a satiation device 120 may be configured, as
shown in FIG. 6, to have an antral tube 10b that is positioned only
within the antrum and that does not cross the pyloric sphincter. As with
the prior embodiments, the satiation device 120 is preferably
self-expanding and may be formed of a soft nitinol, shape memory polymer,
or stainless steel mesh, preferably in combination with a polymer.
Outward radial pressure between the antral tube and the stomach walls
prevent the tube from moving distally through the pylorus, even in the
presence of peristalsis. Additional mechanisms may be provided to prevent
movement of the tube towards the fundus and/or pylorus. For example, soft
and directional "fish scale" type structures 36 may be formed on the mesh
or polymer on the exterior surface of the antral tube 10b as shown in
FIG. 7. The figure shows the scales oriented to prevent movement of the
device towards the pylorus, but it should be appreciated that movement
towards the fundus may be prevented by orienting the scales in the
opposite direction.

[0053] A plurality of hooks 38 may be formed on the proximal and/or distal
ends of the antral tube 10b, as shown in FIG. 8. These hooks gently
attach to the mucosa of the antrum and prevent movement in the proximal
and/or distal direction. Such hooks should be sufficiently small as to
not penetrate the submucosa or muscularis.

[0054] FIGS. 9A and 9B illustrate the use of ridges formed on the exterior
of the antral tube for preventing migration of the tube. The ridges may
be formed in a variety of configurations, such as the helical ridges 40
shown on the FIG. 9A embodiment or the rings 42 shown in the FIG. 9B
embodiment. These same mechanisms for preventing movement may be applied
to the bowel tube as well, as described with respect to FIGS. 10D-10F.

[0055] A basket structure may extend from the proximal end of the antral
tube for positioning in the fundus. Referring to FIGS. 10A-10C, a fundal
basket 44a, 44b, 44c may be formed of a mesh provided with large openings
sized to permit food to readily flow through the fundal basket into the
antral tube. Unlike the mesh of the antral tube, the mesh of the fundal
basket is preferably not covered with a polymeric skin or coating. The
fundal basket is mechanically connected to the antral tube, such as by
spring members 46a (FIG. 10A), elongate struts 46b (FIG. 10B), mesh 46c
(FIG. 10C) or equivalent structural components. The proximal end of the
fundal basket rests against the walls of the fundus of the stomach and
thereby functions to prevent migration of the device within the stomach.
An embodiment utilizing an antral tube and fundal basket may be provided
in a modular form--in which the antral and fundal components are separate
from one another and then attached to one another pre-operatively or
following implantation in the body. Alternatively, the antral tube and
fundal basket may comprise a unitary device.

[0056] Similar attachment mechanisms may be used to attach a bowel tube to
an antral tube in embodiments having these components, regardless of
whether a fundal basket is used. For example, the bowel section 132b and
antral section 110b may be connected with one or more longitudinal
struts, as shown in FIGS. 10E and 10F. An alternative embodiment may be
provided without an attachment strut, in which case bowel tube 132a may
be placed separately from antral tube 110a, and it may include a neck
section 133 (or tabs such as tabs 13 of FIGS. 16A/16B) at its proximal
edge to allow recovery with an endoscopically controlled snare. See FIG.
10D. As discussed previously, a device of this type may be provided as a
modular or unitary device.

[0057] Referring to FIG. 11, embodiments having an antral tube 10b and a
fundal basket 44 may further include a bowel tube 32 attached to the
antral tube. As discussed previously with respect to FIG. 5, the bowel
tube 32 functions to keep food away from the proximal small bowel. The
bowel tube 32 may have properties similar to those described with respect
to the embodiment of FIG. 5.

[0058] As with the previous embodiment, the embodiments of FIGS. 10A-10F
and 11 are preferably inserted into the stomach in a collapsed condition,
such as within a sheath 26 as shown in FIG. 12A. In the case of the FIG.
10A-10C embodiments which include antral and fundal tubes only, the
distal tip of the antral tube is placed at the pylorus (or across the
pylorus as with the FIG. 2 embodiment) and the sheath is withdrawn. As
they are released, the antral and fundal units self-expand and may
shorten slightly.

[0059] If a small bowel tube is to be included, as in FIGS. 10D-10F, the
tube can be placed under radiological guidance or endoscopic guidance or
over a guide wire as described above with respect to FIG. 5. As
discussed, the antral tube, fundal basket and bowel tube may form parts
of a unitary device, or they may be separately provided as modular
components. In a modular device, each of the three components may be
separately provided and then attached to one another prior to
implantation or after the components have been positioned within the
body. In another form of modular device, some but not all of the
components (e.g. the fundal basket and antral tube, or the antral tube
and bowel tube) may comprise a unitary device, and an additional modular
component may be provided for subsequent attachment to the unitary device
either before or after implantation.

[0060] Referring to FIG. 12B, removing the device, whether it includes
only an antral tube, fundal and antral tubes, or fundal, antral and small
bowel tube, is accomplished by extending a sheath 26 into the stomach,
extending a grasping instrument through the sheath, grasping the proximal
end of the device and pulling the tube into the sheath causing it to
collapse. If a wire snare loop is to be used as the grasping instrument,
the snare is placed around a neck (such as neck 16 shown in FIG. 2 or a
similar neck 17 at the proximal end of the fundal basket as shown in FIG.
12B) to grasp the device. Engagement with the snare loop would assist in
collapsing the tube as the snare is tightened around the neck and
withdrawn into the sheath 26. Alternatively, as described with respect to
FIGS. 16A and 16B, the proximal end of the tube may include tabs 13 that
are pulled radially inwardly using an endoscopic instrument to facilitate
collapse of the device.

[0061] Another alternative satiation device 130 is shown in FIG. 13. As
with the prior devices, device 130 includes an antral tube 10c
positionable within the antrum to minimize direct contact between food
entering the antrum and the walls of the antrum. The antral tube 10c may
be formed of a combination of soft polymeric material as well as
reinforcing members formed of nitinol, stainless steel, and/or polymer.
In the embodiment shown in FIG. 13, device 130 is formed of a polymeric
sleeve 48 with nitinol struts 50 embedded in the sleeve material.
Stainless steel or polymeric reinforcing bands 52 extend longitudinally
along the interior walls of the tubular member. Inflatable reservoirs 54
formed of a soft elastic polymer are positioned on the exterior of the
tubular sleeve 48. A fill tube 56 is fluidly coupled to the reservoirs.
After the device is positioned within the antrum, reservoirs 54 are
filled with saline to expand the sleeve 48 into contact with the antrum
walls, so as to hold the device in place within the antrum. Fill tube 56
may detach from the reservoir following inflation using the saline. To
prevent saline leakage, a one-way valve (not shown) may be located within
the reservoir at the point of attachment of the fill tube.

[0062] Another alternative embodiment of a satiation device 200 is shown
in FIGS. 14 and 15. The device may be formed of a wire member coiled to
create a stent-like device. The coil may be contoured to match the
contours of interior lumen wall, such as by forming the coil of a shape
memory material such as nitinol or polymers, and shape setting the
material to the desired shape. Device 200 has a proximal portion 202
positionable in the antrum, and a distal portion 204 that may be
positioned in the duodenum bulb or further within the small intestine.
The pitch of the coil is selected to give the device 200 a desired
strength and flexibility.

[0063] A straight portion 206 connects the proximal and distal portions
202, 204. Straight portion 206 is positionable within the pyloric
sphincter. Under normal conditions, the pyloric sphincter remains closed.
until the stomach is ready to evacuate its contents into the duodenum.
Straight portion 206 is beneficial in that it provides structure
connecting proximal and distal portions 202, 204 while allowing the
pyloric sphincter to correctly perform its normal function.

[0064] Although a preferred material for the device 200 is wire, it should
be noted that a variety of alternative materials may be used for this
purpose. For example, device 200 may be formed of ribbons of material, or
it may be formed from a metallic sheet, or its pattern may be cut from
tubing.

[0065] Yet another embodiment of a satiation device 300 is illustrated in
FIG. 17A. Device 300 includes a tubular pouch 302 that is positioned in
the proximal region of the stomach. Pouch 302 includes a proximal end
that is preferably positioned to be slightly proximal of the
gastroesophageal junction as shown. The walls of the pouch preferably
taper inwardly from the proximal end towards the distal end. A proximal
opening 304 of, for example, approximately 25 to 50 mm in diameter is
located at the proximal end and a distal opening 308 having a diameter of
approximately 6-12 mm is formed at the distal end. The proximal opening
304 is preferably placed into alignment with the esophagus, and the
distal opening 308 opens into the interior of the stomach.

[0066] Because of its small volume (which may be on the order of
approximately 30 cc-50 cc in volume), the pouch functions to limit the
amount of food that can be consumed at one time. Food ingested by the
patient remains in the pouch until digestive enzymes have broken it down
sufficiently for it to pass through the distal opening 308.

[0067] The pouch is preferably self-expanding and may take a variety of
forms. For example, referring to FIG. 18 it may be formed of struts 310
or a mesh formed of nitinol, stainless steel, polymer (including shape
memory polymer). A ring 312 is attached to the struts/mesh at the
proximal end of the device, and also may be formed of nitinol, stainless
steel, polymer (including shape memory polymer). The exterior or interior
of the pouch covered with a material 313 will prevent passage of food
through the sides of the pouch. One example of such a material is a
polyester material such as the polyester sold by the DuPont Company under
the trademark Dacron.

[0068] FIGS. 19A and 19B show another example of a pouch 302a. Pouch 302a
is formed of a shape memory coil that has been heat set to a funnel
shape. Dacron polyester or other material 313a (FIG. 19B) may optionally
cover the interior or exterior walls of the coil, although the coil may
itself be sufficiently small as to prevent migration of food to the
surrounding stomach walls. The material 313a may be pinched between
proximal-most coil 312a and its adjacent coil as shown in FIG. 19B. so as
to hold it in place.

[0069] The pouches 302, 302a may be provided with a proximal-to-distal
dimension that is fairly long (e.g. on the order of approximately 2.5-5.0
cm) and that thus gives the pouch a funnel shape as shown in FIGS. 18 and
19A. However, a variety of alternative shapes may be used for the pouch.
For example, the pouch may have a much shorter proximal-to-distal
dimension and thus take the shape of a shallow saucer with a small hole
on its bottom surface.

[0070] The stomach pouch may be used alone or in combination with other
components. If used without additional components, the proximal end of
the pouch (e.g. ring 312 of pouch 302 or ring 312a of pouch 302a) may
serve as a sewing ring that is attached by sutures to the interior
stomach walls. The suture may pass through the material 313, 313a (see
FIG. 19B) to strengthen the connection between the stomach wall and the
device. Alternatively, the pouch may be used as a standalone device
without sutures--in which case it may be held in place by the radial
expansion forces of the struts, mesh or coils.

[0071] The stomach pouch may alternatively be one portion of a larger
satiation device. For example, referring to FIG. 17B, the proximal
portion of the pouch (such as ring 312 of the pouch of FIG. 18 or the
upper coil 312a of the pouch of FIG. 19A) may be connected to the
proximal end of a larger cage structure 314. Cage 314 extends from the
esophagus to the proximal portion of the antrum, and may be similar to
the fundal baskets described above. It may be a large stent-like
structure preferably formed of self-expanding material, such as stainless
steel or a shape memory material such as nitinol or polymer. Cage 314
functions primarily to distend the stomach to create a feeling of
satiety. As shown, the pouch 300 is suspended into the interior of cage
314.

[0072] Additionally, the pouch (as used with or without cage 314) may also
be attached at its proximal end to an alignment extension 316. Referring
to FIG. 17c, alignment extension 316 is a tubular stent portion that
extends into the esophagus. In one embodiment, extension 316 may be
approximately 5 cm in length. It functions primarily to keep the proximal
opening of the pouch aligned with the esophagus--so that food passing
through the esophagus passes easily into the pouch.

[0073] Finally, an enclosed bypass tail (not shown) may extend from distal
opening 308 of the pouch through the pylorus into the small bowel to
simulate a stomach bypass procedure. The structure of the tail may be
similar to the bowel tube described with respect to FIG. 5.

[0074] The stomach pouch and associated components may be implanted and
removed using procedures of the type described with respect to previous
embodiments. In embodiments in which the stomach pouch includes the cage,
alignment extension, and/or bypass tail, the components may be implanted
simultaneously as a single device. Alternatively, they may be segmented
for separate implantation and for subsequent suture attachment to one
another once they are within the body.

[0075] Another embodiment of a satiation device is illustrated in FIG. 20.
This satiation device includes a duodenal absorption barrier--an elongate
tube 400 that is positionable within the small intestine at a location
slightly distal of the ampulla of vader. For example, the barrier may be
positioned a distance of approximately 1 cm or more from the ampulla of
vader. Positioning of the tube so that it does not contact the ampulla
(an opening through which bile passes into the duodenum) is desirable in
that it minimizes the chance of irritation and choleocystitus.

[0076] The tube 400 is preferably a flexible tube preferably approximately
20 cm or more in length. It may be constructed as described with the
satiation devices described above. For example, it may be formed of a
self-expandable material such as nitinol, stainless steel or a shape
memory polymer (e.g. oligo-(caprolactone)-dimethacrylate or n-butyl
acrylate), and covered with a polymer covering that is resistant to
gastric juices (e.g. silicone) and that prevents passage of food
byproducts through the walls of the tube.

[0077] The tube 400 prevents caloric intake in the small intestine by
preventing absorption of food through the walls of the duodenum, and thus
functions as an aid to weight loss.

[0078] Tube 400 may be delivered and extracted using the techniques
described above, and it may be held in place in any of the ways described
herein, including sutures, barbs, scales, hooks, or under the outward
pressure of the expanded device against the surrounding walls of the
duodenum. Tube 400 may be used alone or in combination with components of
the type described above.

[0079] Various embodiments of satiation device have been described herein.
These embodiments are giving by way of example and are not intended to
limit the scope of the present invention. It should be appreciated,
moreover, that the various features of the embodiments that have been
described may be combined in various ways to produce numerous additional
embodiments.

Patent applications by Fred E. Silverstein, Seattle, WA US

Patent applications by Nathan Every, Seattle, WA US

Patent applications by Richard A. Glenn, Chapel Hill, NC US

Patent applications by Richard S. Stack, Chapel Hill, NC US

Patent applications by Trevor J. Moody, Seattle, WA US

Patent applications by William S. Eubanks, Jr., Durham, NC US

Patent applications by BAROSENSE, INC.

Patent applications in class DEVICES TRANSFERRING FLUIDS FROM WITHIN ONE AREA OF BODY TO ANOTHER (E.G., SHUNTS, ETC.)

Patent applications in all subclasses DEVICES TRANSFERRING FLUIDS FROM WITHIN ONE AREA OF BODY TO ANOTHER (E.G., SHUNTS, ETC.)